“At the house of Mrs. Hollingsworth—­around the point on this side of the bay.  You can’t see it from here.”

“I’d like to go there,” remarked Kennedy.

“Very well.  Car or boat?”

“Boat, I think.”

“Suppose we go in my little runabout, the Streamline II?  She’s as fast as any ordinary automobile.”

“Very good.  Then we can get an idea of the harbor.”

“I’ll telephone first that we are coming,” said Verplanck.

“I think I’ll go, too,” considered Mrs. Verplanck, ringing for a heavy wrap.

“Just as you please,” said Verplanck.

The Streamline was a three-stepped boat which.  Verplanck had built for racing, a beautiful craft, managed much like a racing automobile.  As she started from the dock, the purring drone of her eight cylinders sent her feathering over the waves like a skipping stone.  She sank back into the water, her bow leaping upward, a cloud of spray in her wake, like a waterspout.

Mrs. Hollingsworth was a wealthy divorcee, living rather quietly with her two children, of whom the courts had awarded her the care.  She was a striking woman, one of those for whom the new styles of dress seem especially to have been designed.  I gathered, however, that she was not on very good terms with the little Westport clique in which the Verplancks moved, or at least not with Mrs. Verplanck.  The two women seemed to regard each other rather coldly, I thought, although Mr. Verplanck, man-like, seemed to scorn any distinctions and was more than cordial.  I wondered why Mrs. Verplanck had come.

The Hollingsworth house was a beautiful little place down the bay from the Yacht Club, but not as far as Verplanck’s, or the Carter estate, which was opposite.

“Yes,” replied Mrs. Hollingsworth when the reason for our visit had been explained, “the attempt was a failure.  I happened to be awake, rather late, or perhaps you would call it early.  I thought I heard a noise as if some one was trying to break into the drawing-room through the window.  I switched on all the lights.  I have them arranged so for just that purpose of scaring off intruders.  Then, as I looked out of my window on the second floor, I fancied I could see a dark figure slink into the shadow of the shrubbery at the side of the house.  Then there was a whirr.  It might have been an automobile, although it sounded differently from that—­more like a motor boat.  At any rate, there was no trace of a car that we could discover in the morning.  The road had been oiled, too, and a car would have left marks.  And yet some one was here.  There were marks on the drawing-room window just where I heard the sounds.”

Who could it be?  I asked myself as we left.  I knew that the great army of chauffeurs was infested with thieves, thugs and gunmen.  Then, too, there were maids, always useful as scouts for these corsairs who prey on the rich.  Yet so adroitly had everything been done in these cases that not a clue seemed to have been left behind by which to trace the thief.